Presence sensing in IoT devices usually means keeping a full sensing and processing chain powered to catch motion or occupancy events. A new approach described by Semiconductor Engineering uses 60 GHz radar to monitor continuously while the rest of the chain remains inactive, cutting the energy cost of always-on detection.
The radar operates at 60 GHz, a frequency band that allows the sensor to detect fine motion and presence changes without needing the heavier processing that other sensing modalities require. By keeping only the radar front-end active, the device can wake the rest of the system only when a relevant event occurs, rather than continuously processing raw data.
This design targets battery-powered or energy-harvesting IoT devices where continuous presence sensing has previously been impractical. The trade-off is that the radar may not capture the same level of detail as a fully active sensing chain, but for occupancy and motion tracking, the power savings are the primary goal.